Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753560AbbEKPrH (ORCPT ); Mon, 11 May 2015 11:47:07 -0400 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:47488 "EHLO e23smtp08.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754591AbbEKPkw (ORCPT ); Mon, 11 May 2015 11:40:52 -0400 From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , David Gibson , Benjamin Herrenschmidt , Paul Mackerras , Alex Williamson , Gavin Shan , Wei Yang , linux-kernel@vger.kernel.org Subject: [PATCH kernel v10 11/34] vfio: powerpc/spapr: Moving pinning/unpinning to helpers Date: Tue, 12 May 2015 01:39:00 +1000 Message-Id: <1431358763-24371-12-git-send-email-aik@ozlabs.ru> X-Mailer: git-send-email 2.4.0.rc3.8.gfb3e7d5 In-Reply-To: <1431358763-24371-1-git-send-email-aik@ozlabs.ru> References: <1431358763-24371-1-git-send-email-aik@ozlabs.ru> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15051115-0029-0000-0000-000001863364 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4715 Lines: 160 This is a pretty mechanical patch to make next patches simpler. New tce_iommu_unuse_page() helper does put_page() now but it might skip that after the memory registering patch applied. As we are here, this removes unnecessary checks for a value returned by pfn_to_page() as it cannot possibly return NULL. This moves tce_iommu_disable() later to let tce_iommu_clear() know if the container has been enabled because if it has not been, then put_page() must not be called on TCEs from the TCE table. This situation is not yet possible but it will after KVM acceleration patchset is applied. This changes code to work with physical addresses rather than linear mapping addresses for better code readability. Following patches will add an xchg() callback for an IOMMU table which will accept/return physical addresses (unlike current tce_build()) which will eliminate redundant conversions. Signed-off-by: Alexey Kardashevskiy [aw: for the vfio related changes] Acked-by: Alex Williamson Reviewed-by: David Gibson --- Changes: v9: * changed helpers to work with physical addresses rather than linear (for simplicity - later ::xchg() will receive physical and avoid additional convertions) v6: * tce_get_hva() returns hva via a pointer --- drivers/vfio/vfio_iommu_spapr_tce.c | 61 +++++++++++++++++++++++++------------ 1 file changed, 41 insertions(+), 20 deletions(-) diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index e21479c..115d5e6 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -191,69 +191,90 @@ static void tce_iommu_release(void *iommu_data) struct tce_container *container = iommu_data; WARN_ON(container->tbl && !container->tbl->it_group); - tce_iommu_disable(container); if (container->tbl && container->tbl->it_group) tce_iommu_detach_group(iommu_data, container->tbl->it_group); + tce_iommu_disable(container); mutex_destroy(&container->lock); kfree(container); } +static void tce_iommu_unuse_page(struct tce_container *container, + unsigned long oldtce) +{ + struct page *page; + + if (!(oldtce & (TCE_PCI_READ | TCE_PCI_WRITE))) + return; + + page = pfn_to_page(oldtce >> PAGE_SHIFT); + + if (oldtce & TCE_PCI_WRITE) + SetPageDirty(page); + + put_page(page); +} + static int tce_iommu_clear(struct tce_container *container, struct iommu_table *tbl, unsigned long entry, unsigned long pages) { unsigned long oldtce; - struct page *page; for ( ; pages; --pages, ++entry) { oldtce = iommu_clear_tce(tbl, entry); if (!oldtce) continue; - page = pfn_to_page(oldtce >> PAGE_SHIFT); - WARN_ON(!page); - if (page) { - if (oldtce & TCE_PCI_WRITE) - SetPageDirty(page); - put_page(page); - } + tce_iommu_unuse_page(container, oldtce); } return 0; } +static int tce_iommu_use_page(unsigned long tce, unsigned long *hpa) +{ + struct page *page = NULL; + enum dma_data_direction direction = iommu_tce_direction(tce); + + if (get_user_pages_fast(tce & PAGE_MASK, 1, + direction != DMA_TO_DEVICE, &page) != 1) + return -EFAULT; + + *hpa = __pa((unsigned long) page_address(page)); + + return 0; +} + static long tce_iommu_build(struct tce_container *container, struct iommu_table *tbl, unsigned long entry, unsigned long tce, unsigned long pages) { long i, ret = 0; - struct page *page = NULL; - unsigned long hva; + struct page *page; + unsigned long hpa; enum dma_data_direction direction = iommu_tce_direction(tce); for (i = 0; i < pages; ++i) { unsigned long offset = tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK; - ret = get_user_pages_fast(tce & PAGE_MASK, 1, - direction != DMA_TO_DEVICE, &page); - if (unlikely(ret != 1)) { - ret = -EFAULT; + ret = tce_iommu_use_page(tce, &hpa); + if (ret) break; - } + page = pfn_to_page(hpa >> PAGE_SHIFT); if (!tce_page_is_contained(page, tbl->it_page_shift)) { ret = -EPERM; break; } - hva = (unsigned long) page_address(page) + offset; - - ret = iommu_tce_build(tbl, entry + i, hva, direction); + hpa |= offset; + ret = iommu_tce_build(tbl, entry + i, (unsigned long) __va(hpa), + direction); if (ret) { - put_page(page); + tce_iommu_unuse_page(container, hpa); pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n", __func__, entry << tbl->it_page_shift, tce, ret); -- 2.4.0.rc3.8.gfb3e7d5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/